tsillik, Your Pistol is As Bill stated mid seventies, FI sold the Model D to IJ in 1978 (if I remember correctly) around serial number 40,000. IJ released the pistol as the Pony which then had an off and on production up to the early nineties.
Does your pistol have a long thin spring steel extractor or the conventional type ? How about the barrel, does it have the single locking lug or without and locking on the stepped area at the end of the breech? The second type of barrel has been incorrectly thought to be a blowback change but it actually locks on the forward edge of the ejection port. Another cost cutter by the bean counters.